Rudders in those days were held in place solely by weight keeping the pintles in the gudgeons.
Racing vessels having a different sort of schedule than merchant ships or military ships. A six day race schedule being a bit different than a six month sea cruise--so a bit less impetus to retain a rudder is a following sea tries to lift it out of its gudgeons. That, and the racing community can get finicky about extra weight or extraneous gear aboard.
Fitting a tiller to the head of the rudder is a matter of some mortice and tenon work, with wedges or bolts to fix things in place.. Unlike a tackle-driven wheel, a tiller can be turned at differing speeds. So, you can put the rudder over slowly, or smartly--not being limited by how much friction a wheel's drum can impart on the rudder line. nd in racing, when the rudder needs to go over, it often needs to do so Right Now. A tiller is very sure that way, and with no extra rigging or tackle belowdecks.
So, the preventer/protector lines might well be absent on America (except for when she would make an ocean crossing). The travel stops for the rudder were likely the cockpit coamings.